Acorn Archimedes A310

One of the first ARM machines anybody could buy. The 1987 Archimedes launch put Acorn's own 32-bit processor — designed in-house because nothing on the market was good enough — into a desktop computer running Arthur, later RISC OS. It was faster than anything at the price and had almost no software. The significance is hard to overstate: every ARM core shipped since traces to this design.